<?php
# MantisBT - A PHP based bugtracking system

# MantisBT is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 2 of the License, or
# (at your option) any later version.
#
# MantisBT is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with MantisBT.  If not, see <http://www.gnu.org/licenses/>.

/**
 * PHP Compatibility API
 *
 * Provides functions to assist with backwards compatibility between PHP
 * versions.
 *
 * @package CoreAPI
 * @subpackage PHPCompatibilityAPI
 * @copyright Copyright 2000 - 2002  Kenzaburo Ito - kenito@300baud.org
 * @copyright Copyright 2002  MantisBT Team - mantisbt-dev@lists.sourceforge.net
 * @link http://www.mantisbt.org
 */

/**
 * Constant for our minimum required PHP version
 */
define('PHP_MIN_VERSION', '5.3.2');

/**
 * Determine if PHP is running in CLI or CGI mode and return the mode.
 * @return int PHP mode
 */
function php_mode()
{
    static $s_mode = null;

    if (is_null($s_mode)) {
        # Check to see if this is CLI mode or CGI mode
        if (isset($_SERVER['SERVER_ADDR'])
            || isset($_SERVER['LOCAL_ADDR'])
            || isset($_SERVER['REMOTE_ADDR'])
        ) {
            $s_mode = PHP_CGI;
        } else {
            $s_mode = PHP_CLI;
        }
    }

    return $s_mode;
}

/**
 * Returns true if the current PHP version is higher than the one
 * specified in the given string
 * @param string $p_version_string Version string to compare.
 * @return boolean
 */
function php_version_at_least($p_version_string)
{
    static $s_cached_version;

    if (isset($s_cached_version[$p_version_string])) {
        return $s_cached_version[$p_version_string];
    }

    $t_curver = array_pad(explode('.', phpversion()), 3, 0);
    $t_minver = array_pad(explode('.', $p_version_string), 3, 0);

    for ($i = 0; $i < 3; $i = $i + 1) {
        $t_cur = (int)$t_curver[$i];
        $t_min = (int)$t_minver[$i];

        if ($t_cur < $t_min) {
            $s_cached_version[$p_version_string] = false;
            return false;
        } else if ($t_cur > $t_min) {
            $s_cached_version[$p_version_string] = true;
            return true;
        }
    }

    # if we get here, the versions must match exactly so:
    $s_cached_version[$p_version_string] = true;
    return true;
}

# If mb_* not defined, define it to map to standard methods.
if (!function_exists('mb_substr')) {
    /**
     * Map mb_substr to utf8_substr if mb extension is not found
     * @param string $p_text Text string.
     * @param integer $p_index Start position.
     * @param integer $p_size Size.
     * @return string
     */
    function mb_substr($p_text, $p_index, $p_size)
    {
        return utf8_substr($p_text, $p_index, $p_size);
    }
}
